With Ghent’s famous 6-days of track racing, I decided to stick to singlespeed commuting week too 🙂
Eventually, the Niner will go back and forth between gears and ss. I already have the rd-rx800 in the mail but also a Surly 17t singlespeed sprocket.
I didn’t like the mechanical XT rear derailleur solution, requiring a wolftooth tanpan pull conversion device. DI2 solved that, but then there were the battery issues (turned out to be the ant+ device). Since Shimano released the rd-rx800 with the clutch and 40T sprocket support, no longer need an XT mech and so I can keep this thing rock solid and simple. Just need to install a full-housing cable and be done. It doesn’t apply to this bike with its MTB grade derailleur hanger, but the rd-rx805, the di2 version, is also less brutal on the hanger and supports a front road derailleur too. I have that on the BMC running 1X which I may convert to 2X again. Who knows.
I used to run the chain tensioner like a derailleur, pushing the chain down and out. The disadvantage is that the chain communicates with less teeth on the sprocket and on rougher roads and steps, this causes skipping. Not pleasant at all.
I kind of regret the BSA adaptor now, because I could have gone for an eccentric bottom bracket, instead of a chain tensioner. No, never mind, brain fart.. Threaded bb forever! Also, don’t know how that would have worked with an oval ring.
Here I had an 18T sprocket (Surly singlespeed) and another 17T from a standard shimano ultegra cassette. The chain skipped even on the larger teeth of the surly sprocket.
So then I realizd that Surly had included a second spring for the chain tensioner, to allow it to push the chain up and thus using more of the teeth on the sprocket.
38Tx17T seems to work ok. Incredibly silent everywhere and I do understand why some stick to singlespeed.